New CTEQ global analysis of quantum chromodynamics with high-precision data from the LHC

Tie Jiun Hou, College of Sciences, Northeastern University
Jun Gao, Shanghai Jiao Tong University
T. J. Hobbs, Southern Methodist University
Keping Xie, Southern Methodist University
Sayipjamal Dulat, Xinjiang University
Marco Guzzi, Kennesaw State University
Joey Huston, Michigan State University
Pavel Nadolsky, Southern Methodist University
Jon Pumplin, Michigan State University
Carl Schmidt, Michigan State University
Ibrahim Sitiwaldi, Xinjiang University


We present the new parton distribution functions (PDFs) from the CTEQ-TEA collaboration, obtained using a wide variety of high-precision Large Hadron Collider (LHC) data, in addition to the combined HERA I+II deep-inelastic scattering dataset, along with the datasets present in the CT14 global QCD analysis. New LHC measurements in single-inclusive jet production with the full rapidity coverage, as well as production of Drell-Yan pairs, top-quark pairs, and high-pT Z bosons, are included to achieve the greatest sensitivity to the PDFs. The parton distributions are determined at next-to-leading order and next-to-next-to-leading order, with each of these PDFs accompanied by error sets determined using the Hessian method. Fast PDF survey techniques, based on the Hessian representation and the Lagrange multiplier method, are used to quantify the preference of each data set to quantities such as αs(mZ), and the gluon and strange quark distributions. We designate the main resulting PDF set as CT18. The ATLAS 7 TeV precision W/Z data are not included in CT18, due to their tension with other datasets in the global fit. Alternate PDF sets are generated including the ATLAS precision 7 TeV W/Z data (CT18A), a new scale choice for low-x DIS data (CT18X), or all of the above with a slightly higher choice for the charm mass (CT18Z). Theoretical calculations of standard candle cross sections at the LHC (such as the gg fusion Higgs boson cross section) are presented.